Question

Explain the order of dielectric constants for the following pairs of liquids. a) Carbon tetrachloride (2.2), chloroform (4.8) b) Ethanol (24.3) and methanol (32.6) c) Acetone (20.7) and formamide (110.0)

Answer 1

Answer:

See explanation

Explanation:

Let us have it behind our minds that the dielectric constant reveals the degree of polarity of a molecule. This implies that the more polar a molecule is, the greater its dielectric constant.

Chloroform is a polar molecule while carbon tetrachloride is a nonpolar molecule due to its symmetrical nature. Thus Chloroform has  a greater degree of polarity and consequently a higher dielectric constant.

Methanol is more polar than ethanol because polarity of the molecule decreases as more CH2s are added to the molecule, that is, polarity of the molecule decreases with increase in the length of the carbon chain. Since methanol is more polar than ethanol, it should have a greater dielectric constant.

Again, the presence of more akyl groups in acetone makes it less polar than formamide. Consequently, formamide has a greater dielectric constant than acetone.